cos(2$) 511' 2 ] 2 5111(3) on the interval ['? ? Let x) : (a) Find all critical points (within the given interval) and classify them. Express the critical points in the form (a, f(o)). Show all your work. (b) Find the global maximum and global minimum of f in the given interval. Justify your answer. (c) Determine all intervals of concavity (within the given interval). Show all your work. (d) Sketch the graph of f($) by hand (do not show steps, just a sketch of the final graph)